The present invention relates to checkout systems, and more specifically to a radio frequency identification (RFID) system and method.
RFID technology provides an alternative to bar code reader technology for distinguishing and recording items for purchase. RFID may result in labor savings to retailers, since it may obsolete conventional methods of identifying items.
Some of the uses of RFID technology are disclosed in U.S. Pat. No. 6,019,394 assigned to the assignee of the present invention. This patent is hereby incorporated by reference.
RFID systems generally include single bit systems, memory systems, and intelligent systems.
Single bit systems include single bit labels. A single bit label includes a tuned antenna. The antenna passively reflects a specific frequency RF signal and an RFID reader detects the reflected signal. The RFID label can signal only two states to the reader: xe2x80x9cRFID in the fieldxe2x80x9d and xe2x80x9cno RFID in the fieldxe2x80x9d. This type of label has been used on clothing security tags.
Memory systems include labels with an antenna and a memory. The memory stores information such as store name, article price, and purchase date. An RFID reader reads the information without having to get near the label. The RFID system may also add to the information on the chip. Power for the memory may be obtained from the RF signal itself.
Intelligent systems include labels with a memory, antenna, and computer. Intelligent labels can provide additional functionality helpful to a consumer. Power may be obtained from a battery or from the article, if it is powered. An electronic price label, such as the one manufactured by the assignee of the present invention, may act as an intelligent RFID label.
Generally speaking, increased functionality results in an increase in cost and complexity, with the single bit label being the least complex and least costly. Printed ink antennas have driven down the cost. These antennas are not only less costly than metal antennas, but they are also easier to apply to different types of materials.
Though inexpensive, single bit labels are not useful for distinguishing one item from another. Therefore, it would be desirable to provide an RFID system and method, which is inexpensive yet, conveys item identification number.
In accordance with the teachings of the present invention, a radio frequency identification (RFID) system and method is provided.
According to one embodiment of the invention, the system comprises an RF interrogator which transmits signals at a plurality of different frequencies and which receives first frequencies of the plurality of different frequencies from an item label, and a computer which determines second frequencies of the plurality of different frequencies which were not received by the RF interrogator, and which determines an item identification number from the first and second frequencies by assigning first values equal to a first binary digit to first data bits occupying first data bit positions in the item identification number for the first frequencies and assigning second values equal to a second binary digit to second data bits occupying second data bit positions in the item identification number for the second frequencies.
A method of identifying an item includes the steps of transmitting a plurality of different first signals having a plurality of different frequencies, receiving second signals having second frequencies from an item label associated with the item, determining third frequencies associated with the item label which were not received from the item label, and determining an item identification number from the second and third frequencies, including the substeps of assigning first values equal to a first binary digit to first data bits occupying first data bit positions in the item identification number for the second frequencies, and assigning second values equal to a second binary digit to second data bits occupying second data bit positions in the item identification number for the third frequencies.
It is accordingly an object of the present invention to provide a radio frequency identification (RFID) system and method.
It is another object of the present invention to provide a system and method of identifying items which requires less item orientation and placement in order to identify items.
It is another object of the present invention to provide an inexpensive method of identifying items for purchase.
It is another object of the present invention to supplement or replace the function of barcodes with multiple single bit RFID labels.